Robot vacuum charging unit



FIG. 1 is a perspective view of a robot vacuum charging unit showing our new design;

FIG. 2 is a left side elevation view thereof, the right side being a mirror image;

FIG. 3 is a front view thereof;

FIG. 4 is a top view thereof;

FIG. 5 is a bottom view thereof; and,

FIG. 6 is a rear view thereof. 

CLAIM The ornamental design for a robot vacuum charging unit, as shown and described. 